Manufacture of articles from steel alloys



Patented May 9, 1939 UNITED STATES PATENT oFrlcE MANUFACTURE OF ARTICLES FROM STEEL ALLOYS Friedrich Karl Naumann, Essen, Germany, as-, signor to Fried. Krupp Aktiengesellschaft, Essen-on-the-Ruhr, Germany No Drawing. Original application March 3, 1934,

Serial No. 713,926. Divided and this application September 13, 1937, Serial No. Germany March 20, 1933 8 Claims.

, 699,300, I propose to manufacture articles of this class from steel alloys which contain titanium and if desired one or more of the elements silicon,

1 manganese, nickel, cobalt, chromium, tungsten,

molybdenum and vanadium, the steel alloys suitably containing up to 1% carbon, up to 5% titanium, and if desired up to 30% of one or more of the elements silicon, manganese, nickel, cobalt, chromium, tungsten, molybdenum and vanadium.

In my co-pending application for-Letters Patent, filed March 3, 1934, Serial Number 713,926, of which the present application is a division I have shown that besides titanium also the other elements of group IV of the periodic table, as far as they form carbides in the steel, zirconium and thorium, have the property of rendering steel resistant to the attack of gases that attack and remove carbon, such for'instance as the attack of hydrogen at high temperatures and pressures.

According to the present invention use is made for the manufacture of the articles in question of steel alloys which contain an effective amount of one or more elements selected from the group zirconium and thorium and one or more of elements improving the creep strength of the alloy, viz., chromium tungsten molybdenum and vanadium.

Preferably the content of the elements zirconium and thorium amounts to not over.5% and the carbon content to not more than 1%, while the total content of the elements chromium, tungsten, molybdenum and vanadium may amount about up to 30%. In general, however, a total content of not more than 15% of these elements is found desirable. The balance of the alloy consists substantially of iron with the .normal contents of Mn and Si. The latter content, however, may amount also up to 1.5%.

The addition of one or more of the elements Cr, W, Mo and V has for its object to improve the creep strength of the steel alloys, since this (Cl. 75l26) property is of great importance for the apparatus which operate at elevated temperatures.

The steel alloys which besides the carbideforming element of group IV contain further additions of elements, improving the creep strength of the alloys, show a resistance to carbon-removing gases which far exceeds the effect of these additional elements, as the following test shows:

From two steel alloys, A, B of the following composition Per- Per- Per- Per- Prr Per- Steel cent cent cent cent cent cont 0 Si Mn C r Zr M0 A .7, 0.10 1.43 [L48 L22 0.95 B U. 0.10 1.07 0.58 l.l9 0.5!

tensile test pieces were prepared and likewise heated 100 hours at 600 C. in hydrogen under pressure of 300 at. The test pieces treated in this manner showed the following data of strength: I

wherein by a is marked the state when supplied and by b the state after the test.

This table shows that the steel marked A remained practically unaltered, whilst the steel-B sufl'ered a considerable deterioration of its properties of strength.

Steel alloys have been found particularly suitable for the purposes according to the invention, which contain about up to 0;4-% carbon, up to 2% zirconium, up to 3% molybdenum or vanadium, separate or mixed and it. required up to 10% chromium.

I claim: 1. Articles which in their normal use are subjected to the attack of hydrogen at high hydrogen partial pressures and high temperatures, said usual range for low alloy steels.

2. I-Iydrogenating apparatus having its parts which are subjected to the attack of hydrogen at um; an efiective amount not over of material from the groupwonsisting of zirconium and thorium; the remainder substantially iron with silicon not over about 1.5% and a manganese content within the usual range for low alloy steels.

3. Articles which in their normal use are subjected to the attacl; of hydrogen at high hydrogen partial pressures and high temperatures, said articles beingcomposed of a steel alloy consisting of carbon not over 1%; up to 15% of material from the group consisting of chromium, molybdenum) tungsten, and vanadium; an eflective amount not over 5% of material from the group consisting of zirconium and thorium; the remainder substantially iron with silicon not over about 1.5% and a manganese content within the usual range for low alloy steels.

4. Hydrogenating apparatus having its parts which are subjected to the attack or hydrogen at high pressure and temperature composed of a steel alloy consisting of carbon not over 1%; up to 15% of material from the group consisting of'chromiurn, molybdenum, tungsten, and vanadium; an effective amount not over 5% of material from the group consisting of zirconium and thorium; the remainder substantially iron with silicon not over about 1.5% and a manganese content within the usual range for low alloy steels.

5. Articles which in their normal use are subjected to the attack of hydrogen at high hydrogen partial pressures and high temperatures, said articles being composed of a steel alloy consisting 01' carbon not over 0.4% up to 3% or molyb- 2,1 57,654 about 1.5% and a manganese content within the denum; an eflective amount not over 2% material from the group consisting of zirconium and thorium; the remainder substantially iron with silicon not over about 1.5% and a manganese content 'withinthe usual range for low alloy steels.

6. Articles which in their normal use are subjected to the attack of hydrogen at high hydrogen partial pressures and high temperatures,-

,-molybdenum; up to' 10% chromium; an eflective amount not over 2% of material from the group consisting of zirconium and thorium; the

remainder substantially iron with silicon not over about. 1.5% and a manganese content within the usual range for'low alloy steels.

'7. A process which comprises subjecting a material to be hydrogenated to the influence of hydrogen at high hydrogen partial pressure and high temperature in a container composed of a steel alloy containing carbon not over 1%; up to 30% of material of the group consisting of chromium, molybdenum, tungsten and vanadium; and an effective amount not over 5% of material from the group consisting of zirconium. and thorium; the, remainder substantially iron with silicon not over about 1.5% and a manganese content within the usual range for low alloy steels.

8. A process which comprises subjecting a material to be hydrogenated to theinfluence of hydrogen at high hydrogen partial pressure and high temperature in a container composed of a steel alloy containing carbon not over 0.4%; up to 3% of molybdenum; up to 10% of chromium; an efiective amount not over 2% of material from the group consisting of zirconium and thorium: the remainder substantialy iron with silicon not over about 1.5% and a manganese content within the usual range for low alloy steels.

: FRIEDRICH KARL NAUMANN. 

